Electrical plug-in connector



Aug. 1, 1961 J. MUSSARI, JR

ELECTRICAL PLUG-IN CONNECTOR Filed Dec. 26, 1957 INVENTOR. \70s'epkMUSSCZTt K77:

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United StatesPatent O 2,994,849 ELECTRICAL PLUG-IN CONNECTOR JosephMussari, Jr., 724 16th St., Niagara Falls, N.Y. Filed Dec. 26, 1957,Ser. No. 705,200 1 Claim. (Cl. 339-159) Present day electrical energydistribution methods include a three-wire system in which the differencein potential'between two of the conductors is 230 volts, for example,and the difference in potential between either of those conductors andthe third conductor is 115 volts, for example. In common parlance, twoof the wires or conductors are said to be hot and the third is referredto as neutral. It is common practice to have the potential difierencebetween the two hot wires twice that of the potential difference betweenthe neutral wire and either of the hot wires.

The present invention relates to a plug-in connector suitable for usewith a convenience outlet in the threewire system described supra, andhas as an object the safe provision of electrical energy at thepotential difference existing between the neutral and either of the hotwires and also, if it is so desired, at the potential differenceexisting between the two hot wires.

The invention resides in the combination of elements and arrangement ofparts as hereinafter described and illustrated.

An understanding of the invention will be obtained by reference to thedrawings, in which:

FIGURE 1 is an exterior perspective view of one em bodiment of theinvention;

FIGURE 2 is an exterior perspective view of the same embodiment of theinvention but viewed from the opposite end and with the device rotatedone hundred eighty degrees (180") about its longitudinal axis; and

FIGURE 3 is a diagrammatic sketch illustrating the electrical conductorarrangement of the embodiment of the invention illustrated in FIGURE 1and FIGURE 2.

In FIGURE 1 there is illustrated an embodiment of the invention in whichthe body 1 of the plug-in connector is cruciform, with a longitudinalportion 1a and two oppositely positioned projections 2 and 3; with threeterminal engaging prongs 4, 5 and 6 projecting from the longitudinalpart of the body; and with three prong-engaging terminals 7, 8 and 9within the face of the one projection 2. There is also shown in thisFIGURE 1 a pigtail conductor 10 projecting from the lOngitudinal portion1a of the body 1.

In FIGURE 2 the near face of the longitudinal part 1a of the body 1 isshown as having therein three prongreceiving terminals 21, 22 and 23. Atthe opposite end of the longitudinal portion 1a of the body 1 are showntwo of the projecting prongs 4 and 6 illustrated in FIG- URE 1; thethird prong 5 shown in FIGURE 1 being hidden in this FIGURE 2. Alsoillustrated in this FIG- URE 2 are the three prong-engaging terminals24, 25 and 26 within the face of the other projection 3, and the pigtailconductor 10 projecting from the body 1.

In FIGURE 3 the longitudinal portion 1a of the body 1 and theprojections 2 and 3 from the longitudinal portion 1a of the body 1 areillustrated as broken line circles. The three projecting prongs 4, 5 and6 of the main or longitudinal part 1a of the body 1 are shown as beingelectrically connected to the three prong-receiving terminals 21, 23 and22, respectively, by the three longitudinal conductors 31, 32 and 33,respectively. The upper projection 2 is illustrated as having two of itsprong-receiving terminals 9 and 8 electrically connected to the twoouter longitudinal conductors 31 and 33, respectively, by the twotransverse connectors 37 and 36, respectively. The lower projection 3 isshown as having two of its prong-receiving terminals 25 and 26electrically connected to longitudinal conductors 32 and 31,respectively, by two transverse conductors 39 and 40, respectively. Theother two prong-receiving terminals 7 and 24 of the body projections 2and 3, respectively, are shown to be electrically connected to thepigtail conductor 10 by the conductors '35 and 38, respectively.

As illustrated in FIGURE 3, the three prong-engaging terminals of theone projection 2 are arranged with no two of them being parallel, whichis according to one standard type of plug-in connector. The otherprojection 3, also with three prong-receiving terminals, has the hotterminal 25 and the neutral terminal 26 parallel to each other and thatpermits either a common plug-in connector with two parallel prongs or aconnector with a safety ground prong as Well as the usualtwo parallelprongs, to be plugged into it. I

These two types of plug-in connectors are standard types. One is acommon two parallel prong plug which can be inserted into the parallelprong-receiving terminals of the projection 3 for lighting purposes. Theother is a common three-prong plug having two parallel prongs and onepolarized prong for grounding purposes. This is done through theprong-receiving terminal 24 of the projection 3 which in turn isconnected to grounding out pigtail 10. The pigtail 10 is for the purposeof grounding out the metal shell or housing of all electric motors,drills and other devices requiring grounding out and is designed tocomply with all safety codes.

The device of the present invention can be made of such conventionalmaterials as are used in Underwriters approved plug-in connectors foruse in connection with electrical currents at the voltages for which theplug-in connector herein described is to be used.

The device of the present invention is particularly useful in thoseinstances in which the permanent wiring has not been installed, yet itis necessary to have electrical service available. One such instance isin the construction of a new building. In such cases it is not unusualfor temporary electrical service to be installed at the very beginningof the work or very soon thereafter, and such temporary electricalservice usually is of the three-wire system having two hot conductorsand one neutral, with the diiference in potential between the two hotwires being 230 volts, for example, and the potential difierence betweeneither of the hot wires and the neutral wire being volts, for example.

Some electrical driven equipment used in the construction industryrequires current at 230 volts, for example, and other equipment requirescurrent at 115 volts, for example. To satisfy such requirements it isnecessary to run three wire lines to various parts of the job. Thedevice of the present invention makes it possible to install 230 voltconvenience outlets for the utilization of both 230 volt and 115 voltservice from one convenience outlet. That eliminates the necessity ofinstalling both 230 volt and 115 volt convenience outlets and, moreparticularly, eliminates the dangerous practice of attaching an extrasocket to the prongs of a plug by connecting one wire to the hot screwof said plug and another wire to the common, neutral or ground screw ofsaid plug.

Having thus described my invention, I claim:

An electrical plug-in connector comprising, a body formed of insulatingmaterial, three electrically conductive prongs projecting from oneportion of said body, said prongs being spaced from each other and soshaped that two of the prongs may engage electrically charged contactsof a convenience outlet with the third prong being located and shaped toengage a neutral contact of said convenience outlet, a high voltagestation on said body comprising-three circumferentially spaced openingsin a portion of said body, prong receiving terminals within said bodyrespectively adjacent said openings, three con- 'dnctors encased withinthe body extending respectively from one of said prongs to one of saidprong receiving terminals, and a low voltage station on said body havingtwo substanially parallel laterally spaced slots therein, two prongengageable terminal contacts within the body at said low voltage stationwith one contact accessible through each of said slots, and conductorswithin said body connecting said terminal contacts to one of saidchargeable conductors and to said neutral conductor.

References Cited in the file of this patent UNITED STATES PATENTS2,067,796 Smith Jan. 12, 1937 4 t -OBrien Mar. 16, 1943 OBrien June 20,1944 OBrien June 20, 1944 Eisner Oct. 11, 1949 Harcharek Aug. 21, 1951FOREIGN PATENTS Great Britain June 8, 1937 OTHER REFERENCES ElectricalEngineering, October 1952, pp. 879-902. Electrical Engineering, April1955, pp. 286 291.

